Abstract: A method of fabricating an optical waveguide comprising a plane substrate made of a material having a relatively low refractive index, a plane light propagation layer made of a material having a higher refractive index than the substrate, inserted between two strips of a material having a lower refractive index than its own, and a plane light confining layer of a material having a lower refractive index than the propagation layer. At least one of the layer, meaning either the propagation or the confinement layer, is obtained by causing to circulate in a tube of pure silica the vapors of a gaseous compound of silicon transformable into silica and of a gaseous compound of a doping agent transformable into one of its own oxides and heating said vapors sufficiently to obtain the deposit of a layer of doped silica having a refractive index different from that of the pure silica.

Abstract: A method of fabricating a semiconductor crystal mesa stripe whose waist section is narrower than the upper plane of said mesa stripe. The method comprises the steps of forming a first striped mask on the semiconductor crystal wafer in order to fabricate a prescribed mesa stripe, linearly arranging a plurality of second striped masks, narrower than said first striped mask by the prescribed waist width of the main mesa stripe, on the semiconductor wafer plane at prescribed intervals and in parallel with said first striped mask in order to fabricate monitor mesa stripes; and of subjecting said semiconductor wafer plane to mesa etching.

Abstract: An improved method of manufacturing an optical fibre by vapor phase deposition of layers of cladding and core material for an optical fibre on the inside of a tubular substrate, followed by heating of the tube to cause it to collapse into a preform and drawing of the preform to form the fibre, includes performing the collapse with the introduction of chlorine gas acting as a drying agent. An alternative to chlorine gas is a vapor which decomposes in situ to yield chlorine without producing a solid deposit.

Abstract: The present invention provides a drying apparatus for use in a papermaking machine and comprising at least four press rollers in nip contact with one another in succession in a closed train to define a substantially sealed chamber between the press rollers and chamber end walls. At least one of the press rollers is a hollow roller having a pervious outer wall to support at least one endless felt disposed for advance over an outer support surface of at least some of the rollers and passing through all of the nip contacts. The endless felt is a pervious carrier for a paper sheet to be dried. Resilient support means is provided for at least one press roller. Drive means is also provided for at least one press roller. Conduit means permits air movement through the hollow roller and the chamber. Air displacement means is connected to the conduit means. The air movement passes through the sheet carried on the felt whereby to extract moisture from the sheet and for convection of the moisture by the conduit means.

Abstract: The apparatus for manufacturing the ink jet glass tubes includes a vertical mandrel which receives the tubes one at a time from a feeder and rotates them relative to a pair of gas nozzles for their heating. The tube is heated in an axially limited intermediary zone so as to form an hour-glass shaped profile.The profile of the tube is scanned by a television camera which generates two signals indicative of the internal diameter. These are compared electronically with a stored indication of the desired diameter and the two nozzles are rotated into an inactive position when this diameter is reached. The tube is cut along a plane so as to make the profile of the nozzle coincident with a reference profile by a device including an optical device connected to a cutting wheel to permit comparison of the hour-glass profile of the element with the reference profile. The severed end of the tube is then lapped and covered with a non-wettable material.

Abstract: An improved method for deresination of wood chips or pulp is provided. The method comprises contacting the chips or pulp with an ethoxylated alkyl phenol deresinating composition during processing to reduce the level of natural resins present therein. The improvement comprises substituting a sufonated fatty acid for part of the ethoxylated alkyl phenol while maintaining substantially the same level of deresination.

Abstract: Separating elements (14) arranged about a central shaft (1a) rotate in common about the main axis (A) and individually about their longitudinal axes (B). A centrifugal distributor (6) distributes fine-grain mineral mixture mixed with fluid uniformly to the separating elements (14). In each separating element (14) the partial material flow (2a) is set in rotation about the longitudinal axis (B) by entrainment vanes (18) arranged in a first separating element section (15a) and the heavy fraction is centrifuged on to the separator wall (16a). In the second section (15b), formed as conical tubular worm conveyor, which contains no entrainment vanes, the heavy fraction is transported to the collecting chamber (21) and discharged through first discharge openings (22), the fine-grain mineral mixture being fluidized in pulsation on the separating wall (16b) by the combined rotating movements and the heavy fraction being concentrated.

Abstract: An extended nip press for removing water from a traveling web in a paper machine including a press roll with an elongate shoe having a concave surface facing the roll and forming an extended nip therebetween with the shoe pressed to the roll and mounted to accommodate movement to form a wedge of lubricant between the shoe and a belt with the ends of the belt closed by end walls to contain lubricant within the belt and a flexible radial connection between the end walls and the ends of the belt so that the belt will follow the curvature of the nip beyond the ends of the shoe and will flex only in a single plane of the nip.

Abstract: The invention provides a reagent composition for detecting peroxidase-like activity in aqueous media, particularly for determining occult blood in fecal matter "in-the-bowl". The reagents comprise a dry mixture of a 3, 3', 5, 5' -tetramethylbenzidine and an alkali metal perborate, such as sodium perborate, and preferably also including a strong organic carboxylic acid such as citric acid and a sequesterant for trace metals such as ethylenediaminetetraacetic acid. The composition can be made increasingly more stable by coating the tetramethylbenzidine and an antioxidant with a water soluble polymer and or film coating the sodium perborate with a coating at least partially soluble in water. The reagents are deposited in porous or holed matrices including adsorbent paper, gelatin and molded polysaccharide film.

Abstract: An apparatus for recovering gold from gold-containing mixtures by forming a gaseous effluent of said mixture and bringing it into contact with baffles which are arcuately disposed in series so as to divert the gold onto collecting trays. The trays are disposed within a chamber in such manner as to create pathways for the effluent so that divergent streams of said effluent are directed to the baffles to enhance the recovery operation.

Abstract: In an apparatus for synthesizing polynucleotide including a plurality of reactors, bottles charged with reagents and solvents, and change valve means for switching passages between respective bottles and the reactors, the improvement comprises mode selector means between a pressure source and the reactors for switching liquid supply or discharge operation and distributor means for closing or opening passages connected with the reactors to selectively operate the reactors.

Abstract: A isothermal rebreathing apparatus and method for collecting human breath samples for chemical analysis of the ethyl alcohol content wherein the breath samples are obtained from a subject repetitively exhaling into the inhaling from an enclosed, flexible, variable volume, bag-like collection receptacle which is heated to maintain the breath sample enclosed therein at a prescribed temperature, preferably at or near the subject's body temperature, before extracting the breath sample for subsequent chemical analysis. The collection receptacle may be enclosed by an airtight chamber including heaters therein to warm the air around the collection receptacle in order to regulate the temperature of the breath sample therein. A bellows section in fluid communication with the heating chamber allows for inflation and deflation of the flexible collection receptacle while located in an airtight environment.

Abstract: A method for precisely controlling the profile of an opening etched in a layer of material, for example, an insulating layer. In one embodiment, wherein a silicon dioxide layer is reactive ion etched through a photoresist mask, the concentration of a reactive species in an etchant gas is changed during the etching process to change the slope of the opening, the upper sidewall portion of the opening having a shallow slope and the lower sidewall portion of the opening having a steep slope. The final slope of the opening formed by this method is independent of the initial slopes of the images developed in the photoresist mask.

Abstract: A chemical-mechanical (chem-mech) method for removing SiO.sub.2 protuberances at the surface of a silicon chip, such protuberances including "bird's heads". A thin etch stop layer of Si.sub.3 N.sub.4 is deposited onto the wafer surface, which is then chem-mech polished with a SiO.sub.2 water based slurry. The Si.sub.3 N.sub.4 acts as a polishing or etch stop barrier layer only on the planar portions of the wafer surface. The portions of the Si.sub.3 N.sub.4 layer located on the top and at the sidewalls of the "bird's heads" and the underlying SiO.sub.2 protuberances are removed to provide a substantially planar integrated structure.

Abstract: Disclosed is a system for inspecting the attached state of a separable end stop attached to a slide fastener. The system is used with an apparatus for manufacturing a slide fastener equipped with a separable end stop. Fastener stringers are transported by a transfer unit while a separable end stop is attached to the stringers and a completed slide fastener is discharged by a discharge unit. The discharge unit operates in a first state for engaging and feeding a slide fastener, and a second state for allowing a slide fastener to pass freely therethrough. The transfer unit passes a slide fastener through the discharge unit and transports the slide fastener to an inspection apparatus located downstream of the discharge unit.

Abstract: The subject matter of the invention mainly relates to the technical areas of foundry, manufacture of parts by casting metal in moulds.The process consists in that after moulding the parts and stripping them from the moulds which were broken, during a first cycle the mixture resulting from the knock-out is recovered. This mixture being stored. This mixture is directed from the storage place to an intermediate container; then the mixture from the intermediate container is fed up to a sieve grading separator unit allowing to separate the grains or particles in several different grading batches; each one of these batches is directed to a separating table designed for separating chromite from silica; the chromite on the one hand and the silica on the other hand are recovered in containers.This invention mainly applies to the recovery of components of different densities, especially chromite and silica.

Abstract: Disclosed is a process for the purification treatment of liquid reaction and/or washing media obtained in the preparation of cellulose ethers which comprises distilling and subsequently ultrafiltering the media. In the distilling step, the low-boiling organic by-products of the reaction, the residual, non-reacted, low-boiling organic reaction components and/or the optionally used organic solvents are separated in the form of a distillate. The aqueous distillation residue, which particularly comprises salts, a cellulose constituent and possibly medium and/or high-boiling organic by-products of the reaction and/or non-reacted organic reaction components, is thereafter subjected to ultrafiltration. Ultrafiltration results in a permeate, in which the COD values are, for example, reduced by about 20% by weight.

Abstract: Vapor from liquid ethylene dibromide (EDB) functions in a manner superior anhydrous HCl for in situ gas phase etching of InP substrates in Metalorganic Vapor Phased Epitaxy (MOVPE). The etch rate and surface morphology behaviors have been determined for conditions useful as a substrate cleaning step prior to growth of InP and InGaAs epilayers. The thermally activated decomposition and etching are analogous to group III-V semiconductor growth processes; the behavior in different carrier gas mixtures demonstrates dependence on gas phase reactions in the heated vapor above the substrate.

Abstract: The invention relates to a screen surfacing with exchangeable screen elements fastened juxtaposed, which are fastened on a load-bearing substructure. A plastic profile (2) which engages under the edges of at least two mutually adjacent screen elements (14, 15) is fastened on the load-bearing substructure (1) in the region in which two adjacent screen elements (14, 15) adjoin mutually. A second, upper profile (8) is fastened detachably over this plastic profile (2), and a screen element (14, 15) is retained and clamped between the first and second profile on each of two sides.

Abstract: Process and apparatus are disclosed for increasing argon recovery in conjunction with cryogenic distillation of air to high purity oxygen. The increased argon recovery is obtained by incorporating one or more latent heat exchangers in the flowsheet at strategic disclosed locations and between specific fluids. The invention is particularly advantageous in conjunction with LOXBOIL flowsheets, which otherwise lose O.sub.2 recovery when argon recovery is increased.